JPH10265869A - Silicon carbide series fiber-reinforced titanium-alum. series intermetallic compound composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an SiC series fiber/TiAl composite material, on the boundary between SiC series fiber and a matrix, by forming a carbon layer and a tungsten layer from the fiber side. SOLUTION: As for the formation of the carbon layer and the tungsten layer, before the fiber and matrix are compounded, as coating, they are formed on the surface of the fiber. As coating forming means, CVD, PVD, thermal spraying, plating or the like can be adopted. In this case, at first, the carbon layer is formed to prevent the damage from the outside in the fiber, and on the surface of the carbon layer, the tungsten layer preventing its excessive reaction with the matrix. In this way, the carbon layer and tungsten layer on the surface of the fiber suppress the excessive reaction between the fiber and TiAl matrix and furthermore prevent the physical damage of the fiber, by which cracks which have been generated in the conventional compounded preformed body can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
SiC fiber reinforced TiAl-based intermetallic compound composite material (hereinafter referred to as Si) having a carbon layer and a tungsten layer at the interface between the C-based fiber and the TiAl-based intermetallic compound serving as a matrix.
C-based fiber / TiAl composite material).

[0002]

2. Description of the Related Art Commercially available SiC fibers have a carbon layer formed on the surface thereof.
In general, a composite material is formed by compounding a SiC-based fiber and a TiAl-based intermetallic compound.

[0003]

SUMMARY OF THE INVENTION Conventional SiC fibers /
In the TiAl composite material, the fiber (SiC) and the matrix (Ti
Al) causes and promotes excessive reactions at the interface.
As a result, fibers are deteriorated, an embrittlement phase is generated at the interface, and cracks occur in the matrix of the composite body (composite material), and a healthy molded body cannot be obtained. There was a problem that it became low.

[0004] Therefore, it is necessary to suppress (or reduce) the interfacial reaction between the fiber and the matrix. For that purpose, it is necessary to form a reaction barrier layer at the interface, but at this time, a problem is to select what functions as a barrier. The properties required for this barrier material are that the SiC-based fiber (reinforcing fiber) and the matrix TiAl are excellent in chemical and physical (relaxation of thermal stress caused by a difference in linear expansion coefficient between the fiber and the matrix) excellent applicability. It is. The present invention seeks to eliminate the disadvantages of the conventional SiC fiber / TiAl composite material by selecting the barrier layer material.

[0005]

SUMMARY OF THE INVENTION The present invention is a composite material comprising SiC-based fibers as reinforcing fibers and a TiAl-based intermetallic compound as a matrix. Is a SiC-based fiber reinforced TiAl-based intermetallic compound composite material, characterized in that

That is, according to the present invention, W (tungsten) having excellent chemical compatibility with TiAl of the matrix (less reactive with TiAl) is selected as a barrier layer for suppressing the above-mentioned interfacial reaction to prevent fiber damage. And C (carbon) as a barrier layer having excellent physical compatibility with the matrix. That is, the SiC-based fiber and T
Two layers of W and C are provided at the interface with the iAl matrix.

In producing the composite material of the present invention,
The W layer and the C layer are formed as a film on the surface of the SiC-based fiber before the SiC-based fiber and the TiAl matrix are combined. The film forming means may be any of CVD, PVD, thermal spraying, plating and the like. At this time, first, a carbon layer is formed to prevent the SiC-based fiber from being damaged from outside,
A W layer is formed on the surface of the carbon layer to prevent excessive reaction with the matrix.

According to the present invention, according to the present invention, the C layer and the W layer on the surface of the SiC fiber suppress the excessive interfacial reaction between the fiber and the TiAl matrix, prevent the fiber from being physically damaged, and use these barrier materials. Provided is a SiC / TiAl composite material that prevents cracking of a composite molded article that would otherwise occur.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS SiC used in the present invention
As the system fiber, a polymer made of polycarbosilane, polytitanocarbosilane or polyzircocarbosilane is spun and baked, or a diameter of SiC vapor-deposited on the surface of a tungsten fiber or carbon fiber serving as a core by a CVD method: 50 For example, a SiC-based fiber of about 142 μm is used. Further, TiAl-based type γ as intermetallic compounds, alpha ₂ type, those Ortho ROM big the (orthorhombic) is used.

In the present invention, the thickness of the carbon layer formed on the SiC fiber is generally 0.1 to 5 μm, and the thickness of the tungsten layer is generally 0.2 to 50 μm. These layers may be formed by any of a CVD method, a PVD method, a thermal spraying method, and a plating method.

[0011]

EXAMPLES Hereinafter, specific examples of the method for producing a SiC-based fiber-reinforced TiAl-based intermetallic compound composite material of the present invention will be described to clarify the effects of the composite material of the present invention.

(Example 1) Referring to FIG. 1 which is an enlarged schematic view,
The production method and product of the composite material of the present invention will be described. Using carbon fiber (1) as a core, S
Diameter of deposited iC layer: about 140 μm SiC fiber (2)
A fiber (trade name: SCS-6; US Taxtron Specialty Maleria) having a carbon layer (3) formed at about 3 μm by CVD method
ls) was formed to a thickness of about 2 μm on the surface by CVD. The SCS-6 fiber coated with the W layer (4) was wound on a drum having a diameter of 500 mm at a pitch of about 0.2 mm.

On the fiber wound on the drum, a matrix (5), γ-type Ti-48Al-2Cr
Ar gas atomized powder of -2Nb (atomic%) was sprayed by low-pressure plasma spraying shown in Table 1 below to produce a sprayed preform.

[0014]

[Table 1]

Four layers of the above-mentioned thermal spray preform are laminated, and both surfaces of the laminated body are made of Ti-48Al-2Cr-2Nb (at
(thickness: about 200 μm), and the laminate was HIPed at a temperature of 1075 ° C., a pressure of 1500 atm, and a time of 2 hr to form a composite. This composite molded body (composite material) was a sound molded body without any cracks or the like in the matrix (5).

(Example 2) Referring to FIG. 2 which is an enlarged schematic view,
Another embodiment of the present invention will be described. Medium-diameter approximately 30 μm spun and fired from polytitanocarbosilane as raw material
SiC fiber (2) (trademark Tyranno fiber: Ube Industries)
The carbon layer (3) is formed by CVD (source gas: C ₂ H ₆ ,
Carrier gas: Ar, C ₂ H ₆ / Ar amount ratio: about 1/2
0, temperature: 1100 ° C.) to a thickness of 0.7 to 1.1 μm, and further a W layer (4) is formed thereon by a CVD method (source gas: WCl ₆ , carrier gas: H ₂ + Ar (equivalent mixture) Gas), WCl ₆ / carrier gas amount ratio: about 1/50, temperature: 650 ° C.) to form about 2 μm.

Ti-48Al-2Cr-2 obtained by Ar gas atomizing a medium and large diameter Tyranno fiber bundle coated with C and W.
The powder was passed through a slurry of Hb powder (sieved to 60 μm or less), impregnated with the powder in the fiber bundle, pulled up, wound around a drum having a diameter of 500 mm, and dried. The wire preform obtained by the slurry method is cut and laminated, encapsulated in a HIP capsule with a tube, and the capsule is heated from room temperature to 450 ° C. at 2 hours while being evacuated from the tube in the encapsulated state.
For 5 hours and vacuum degassing was performed. Next, the temperature of the capsule was further raised to 550 ° C. at 1 hour, and the capsule was heated at 550 ° C. for 2 hours.
Then, the tube is sealed in a vacuum degassed state, and the inside of the capsule is vacuum sealed. The vacuum-sealed capsule is heated at a temperature of 1075 ° C., a pressure of 1500 atm, and a time of 2 hours.
Was used to composite the internal preform laminate. This composite molded body (composite material) was a sound molded body without any cracks or the like in the matrix (5).

[0018]

The C layer and the W layer are made of SiC fiber and Ti.
The physical and chemical compatibility of the interface with the Al matrix is improved, and cracks and the like do not occur in the matrix of the composite molded article (composite material), and a sound molded article can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partial explanatory view of a first embodiment of the present invention.

FIG. 2 is a partial explanatory view of a second embodiment of the present invention.

Claims (1)

[Claims] An SiC-based fiber is used as a reinforcing fiber, and TiAl is used.
A SiC-based fiber-reinforced TiAl-based intermetallic compound composite material comprising a matrix containing an intermetallic compound as a matrix, wherein a carbon layer and a tungsten layer are formed from the fiber side at the interface between the fiber and the matrix. .